1. Field of the Invention
This invention pertains to a hydraulic reciprocating device and more particularly to a hydraulic reciprocating drill, wherein, a piston continuously communicates with pressurized fluid on one side and intermittently communicates with a hydraulic pressure source on the other side.
2. Description of the Prior Art
Fluid reciprocating devices have found many uses, such as down-the-hole drilling. The fluid reciprocating devices include both pneumatic and hydraulic reciprocating devices. It is desired to obtain a hydraulic reciprocating device that reciprocates as fast as pneumatic reciprocating devices but uses less energy.
U.S. Pat. No. 2,876,742 to Sherrill relates to a variable speed fluid pressure actuated impact device, and more particularly, to a device of this character of a type wherein the impact member is rotatable. The device includes a rotating valve driven by an external motor.
U.S. Pat. No. 3,327,790 to Vincent et al relates to a fluid actuated tool for applying repeated percussive blows to a drill bit in the drilling of oil and gas wells. In particular, the patent concerns percussive motors for incorporting in drill strings causing drill bits to vibrate or oscillate axially at the same time they are being rotated for the drilling of such wells.
U.S. Pat. No. 2,402,300 to Shimer relates to fluid actuated mechanisms and systems. A rotary valve is employed to port fluid alternatively to opposite ends of a piston.
U.S. Pat. No. 3,484,204 to Caviness relates to a reactor for mixing viscous liquids under inert conditions and more particularly to a reactor having a plunger-type agitator for reacting highly viscous liquids under inert conditions in very small quantities. The device has a rotating valve which supplies pressure alternatively to the end of a rod.
U.S. Pat. No. 4,103,591 to Reiersdal relates to a device for hydraulically driven percussion hammer for activating a tool, especially intended as a drilling hammer. The device discloses a rotating valve that admits oil to a chamber and then vents the oil to a return line. The impact piston is driven upwards by this oil so that a surface on the top of the piston is charged with pressure and accumulated. When the bottom end of the piston is vented as the rotary valve turns, the piston is driven downwards by the accumulated pressure.